Perales-Perez O. – Page 2 – TechConnect Briefs

Composition- and Size-Controlled Synthesis of Mn-Zn Ferrite Nanocrystals for Potential Magnetocaloric Applications

Calderón-Ortiz E., Perales-Perez O., Urcio S., University of Puerto Rico-Mayagüez, PR

The use of ferromagnetic fluid for cooling applications where the fluid can be pumped with no moving mechanical parts, using the magnetocaloric effect, can be a great advantage for many applications where maintenance or power [...]

Synthesis and Characterization of Co-Zn Ferrite Nanocrystals for Magnetocaloric Applications

Urcia-Romero S., Renteria B., Gutiérrez G., University of Puerto Rico, PR

Cobalt ferrite (CoFe2O4) is known for its high coercivity, chemical stability and high sensitivity of its Curie temperature (TC) with Zn-doping. A ferrofluid bearing this type of ferrite nanocrystals could be then considered good candidate [...]

Effect of Rare Earth Doping on Magnetic Properties of Cobalt Ferrite Nanocrystals

Cedeño-Mattei Y., Uwakweh O.N.C., Osorio-Cantillo C., University of Puerto Rico-Mayagüez, PR

Cobalt ferrite (CoFe2O4) is a highly anisotropic magnetic material due to the magnetocrystalline anisotropy contribution from Co2+. The addition of foreign cations of different oxidation states, substituting Co2+ or Fe3+, can lead to an atomic [...]

Synthesis and Characterization of Nanocrystalline Eu3+-doped Gd2O3

Jáuregui-Rosas S., Tomar M., Jia W., Vásquez O., Fachini E., University of Puerto Rico, Mayaguez Campus, PR

Nanocrystalline Gd2-xEuxO3 phosphors by a simple sol-gel method have been synthesized. The effects of the annealing temperature and atomic fraction of Eu3+ ions (x) on the structural and luminescence properties of the mixed oxides have [...]

Sorption of Ethylbenzene, Toluene and Xylene onto Crumb Rubber from Aqueous Solutions

Alamo-Nole L.A., Roman F., Perales-Perez O., University Of Puerto Rico at Mayaguez, PR

Crumb rubber is composed of a complex mixture of elastomers (polyisoprene, polybutadiene and styrene-butadiene) and carbon black, as reinforcing agent, among other compounds. The contents of carbon black and the presence of the elastomeric matrix [...]

Sorption of Ethylbenzene, Toluene and Xylene onto Crumb Rubber from Aqueous Solutions

Alamo-Nole L.A., Roman F., Perales-Perez O., University Of Puerto Rico at Mayaguez, PR

Crumb rubber is composed of a complex mixture of elastomers (polyisoprene, polybutadiene and styrene-butadiene) and carbon black, as reinforcing agent, among other compounds. The contents of carbon black and the presence of the elastomeric matrix [...]

Low-Temperature Polyol Synthesis of Nanocrystalline Co and CoPt Alloys

Chávarri-Pajares E., Pérez J., Perales-Perez O., Singhal R., Tomar M.S., University of Puerto Rico, PR

The strong size-dependent magnetic properties of transition metal nanocrystals can be used to estimate the scaling limits of magnetic storage, a key component of information technology. High Ku (magnetocrystalline anisotropy constant) materials become then very [...]

Zinc Sulfide and Cadmium Sulfide based Nanocrystals and Shells

Balaguera M., Perales-Perez O., Rivera-Montalvo L., Singhal R., Tomar M.S., University of Puerto Rico, PR

The objective of the current research is to synthesize CdS, ZnS nanocrystals through a two phases-method were quantum dots moved from the aqueous phase to the organic one after proper coating of the particles by [...]

Effect of Reaction Temperature on the Structural and Optical Properties of Zno Nanocrystals

Parra-Palomino A., Sotomayor C., Perales-Perez O., Singhal R., Voyles P., Tomar M.S., University of Puerto Rico, PR

The present research addressed the size-controlled synthesis of ZnO nanocrystals at different temperatures. In order to study systematically the dependence of crystal size with synthesis conditions in ethanol, stable suspensions of these nanocrystals were produced [...]

Low-Temperature Synthesis and Characterization of Fe-Doped ZnO Nanocrystals

Parra-Palomino A., Singhal R., Perales-Perez O., Tomar M.S., University of Puerto Rico, PR

We present here our results on synthesis and characterization of bare and Fe-doped ZnO nanocrystals by a modified sol-gel method, which does not require annealing of the samples. Metal acetate solutions in 2-ethylhexanoic acid were [...]